I'd be looking hard for specs. That'll tell you the story.
The biggest issue with assembling an AR isn't so much getting the parts together right - it's getting the right parts together.
US Army 1966-69, VFW Life Member, Retired Geek
Not to hijack your thread but I saw a Troy upper for $699 at a local gunshow, I asked the old folks running the booth if the made a mistake. They told me the price was correct, they also said it was ordered from Troy and was all original. If I had the money it would have been mine... Oh well, it wasn't meant to be :-(